tailieunhanh - Advanced Biomedical Engineering Part 3

Tham khảo tài liệu 'advanced biomedical engineering part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Pulse Wave Analysis 31 Arrhythmia is a common abnormal electrical activity in cardiovascular system. The heart rate might go too fast or too slow which will cause the waveforms change shape among continuous pulses. This feature can be captured in both time domain and frequency domain. The basic feature in time domain is time variance among continuous pulses exceeding the average level. The incomplete waveforms and merged waveforms often result in the pulse detection fails which is also a sign of arrhythmia. Eight typical arrhythmia waveforms have been identified from testing data and the patients do have arrhythmia history on file. Features from FFT are helpful to detect some disease or certain cardiac condition but it s difficult to achieve high accuracy by frequency domain analysis only. Wavelet transform is well known for localized variations of power analysis. It uses the time and frequency domains together to describe the variability. Wavelet functions are localized in space while Fourier sine and cosine functions are not. Analyzed Signal length 671 Analyzed signal length 671 Scale of colors from MIN to MAX Fig. 9. Wavelet transform for pulse wave with no diastolic component. Fig. 10. Wavelet transform for pulse wave with clear diastolic component. The algorithm can extract information from many kinds of data including audio and images especially in geophysics fields. It has been used to analyze tropical convection Weng 1994 32 Advanced Biomedical Engineering the El Nino-Southern Oscillation Gu 1995 atmospheric cold fronts Gamage 1993 central England temperature Baliunas 1997 the dispersion of ocean waves Meyers 1993 wave growth and breaking Liu 1994 and coherent structures in turbulent flows Farge 1992 . Wavelet provides multi-resolution analysis to the source data that make the result more adequate for feature detection. Fig. 9. and Fig. 10 show the difference between pulse wave with diastolic component and pulse wave without diastolic component. Diastolic .

TỪ KHÓA LIÊN QUAN
crossorigin="anonymous">
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.